The F word is back. Back in the financial markets, back in the conclaves of central bank governors, back among the manufacturers and the high-street retailers. The four-letter word is fear.

Back in the spring, few imagined that we would be approaching the third anniversary of the collapse of Lehman Brothers on 15 September with such a sense of unease. The belief in early 2011 was that economic recovery was now well enough embedded for central banks to start raising interest rates and for finance ministries to crack on with the job of reducing budget deficits.

Although pockets of optimism remain, the mood today is different. Ben Bernanke, the chairman of the Federal Reserve, has said the US central bank will discuss possible ways to stimulate growth when it meets next month. The Bank of England appears to be heading in a similar direction. There is anxiety at the International Monetary Fund that blanket austerity will tip fragile western economies back into recession. Concerns are once again being expressed about the health of the banks, about America's national debt and, above all, about whether the eurozone can survive its current crisis intact.

Standard Chartered and HSBC were the two UK-based banks to emerge relatively unscathed from the first financial crisis, partly because their global reach allowed them to benefit from the rapid recovery in Asia. This, though, is how the chief economists at the two banks see things.

"America is drowning in debt, Europe is imploding as problems in the euro area intensify, while, in contrast, Asia's economy is cooling, as growth rates moderate from a strong to a solid pace," says Gerard Lyons at Standard Chartered. Putting the possibility of a recession in the US as high as one in three and of an eventual euro crisis as high as one in two, Lyons adds: "It should be little surprise that there is increased uncertainty and heightened risk aversion across financial markets."

Stephen King at HSBC describes the world as a "frozen economic tundra", with the power of central bankers to influence events on the wane. "After the Great Recession, there has sadly been no 'Great Recovery'," King says. He too is unsurprised that investors are rushing for the exit, given the bickering between Democrats and Republicans on how to tackle America's budget problems, and the inability of Europe's politicians to sort out the single currency.

"The west is increasingly looking like a bad version of Japan. And, like Japan, our political leaders are offering few answers."

Collapse

This is not how it was supposed to be. It took time for policymakers to comprehend the enormity of the shock administered to the global economy by the collapse of the US housing market, but once the penny dropped in the autumn of 2008, they were at pains to show that lessons had been learned from the 1930s. Banks were recapitalised to prevent them from going bust, interest rates were slashed, money was created, public spending was increased.

To widespread relief, there was no second Great Depression. Unemployment in the US rose to almost 10% but not the 25% seen in the 1930s. Industrial production and international trade started to pick up in the spring of 2009. By and large, countries resisted the temptations of protectionism.

Over time, however, it has become clear that the recovery has been both slow and costly. If it is aborted, the risk is that the global economy will return to where this all started in 2007, with another crisis in the banking system. The recovery has been slow because the crisis was caused by over-indebtedness among private individuals and banks. Both, in the jargon of the markets, were over-leveraged: they had borrowed an awful lot of money, in other words, in anticipation of asset prices going up and up. When the bubbles burst, households and banks realised how exposed they were. As a result, they started to pay off their debts and even when the cost of borrowing came down to virtually zero, the demand for credit remained weak.

As HSBC's King notes: "The ambient noise of deleveraging is now deafening." But western economies have become so dependent on debt-driven growth in the good years that they are finding the sobering-up process painful. As things stand, it will take the UK longer to return to pre-recession levels of output than it did in the 1930s.

What's more, this lacklustre recovery has not come cheap. As private demand fell, governments stepped up their spending. They cranked up the electronic printing presses, they bought shares in banks and they allowed budget deficits to balloon, gambling that any damage to the public finances would be temporary. Again, things have hardly gone according to plan. Quantitative easing has proved a double-edged sword: it has flooded financial markets with cash and may well have underpinned activity. But it has also pushed up commodity prices, leading to higher inflation and a squeeze on real incomes that has held back recovery.

By effectively nationalising a good chunk of the debts accumulated by the private sector, western governments have now raised concerns about their own solvency. The US has seen its credit rating downgraded; Europe's problems are even more acute after bailouts for Greece (twice), Ireland and Portugal, followed in the past month by emergency action by the European Central Bank to drive down the interest rate on Italian and Spanish bonds.

Just as in the summer of 2008, the assumption is that the global economy will experience a slowdown but not a full-blown contraction. Central banks are still providing massive amounts of monetary stimulus through record-low interest rates, even though finance ministries are tightening fiscal policy by raising taxes and trimming spending. Large corporations outside of the banking sector have money in the bank that could be used for new investment. And consumers should feel better off next year as inflation falls.

Soft landing

Financial markets want to believe the "soft landing" scenario but somehow can't quite bring themselves to do so. The fear comes from the knowledge that commercial banks in Europe are up to their eyeballs in sovereign debt from the weaker peripheral countries, so a default would trigger a feedback loop back into the financial system. Banks have more capital than they had three years ago and are less heavily leveraged. Yet there are doubts about whether they could survive a double-dip recession. And until consumers are spending more freely, there will be a temptation for companies to hoard their cash rather than invest it.

Economic downturns usually go through five distinct phases: bubble, denial, acceptance, panic and recovery. This fifth phase officially started two and a half years ago, but the drip-drip of disappointing news from the around the world in recent weeks has made financial markets highly averse to taking risks. Higher unemployment, slower growth, currency tensions have all led to a rush for safe havens.

The markets are now wondering whether this is one of the rare crises that has a sixth phase – relapse. At root, the suspicion is that the problems that caused the crisis in the first place have not been solved, that politicians are offering weak leadership, and that the next few months could see the start of phase two of the Great Contraction.